Scrutinizing individual CoTPP molecule adsorbed on coinage metal surfaces from the interplay of STM experiment and theory
Scrutinizing individual CoTPP molecule adsorbed on coinage metal surfaces from the interplay of STM experiment and theory
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DOI：
10.1016/j.susc.2014.12.011
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发表时间：
2015-05-01
期刊：
影响因子：
1.9
通讯作者：
Bocquet, Marie-Laure
中科院分区：
文献类型：
--
作者：
Houwaart, Torsten;Le Bahers, Tangui;Bocquet, Marie-Laure
在密度泛函理论（DFT）框架下，对四苯基钴卟啉（CoTPP）分子及其在铜和银表面的吸附进行了比较分析.不同的交换相关泛函-局部密度近似（LDA）和梯度广义近似（沿着与PEE功能和半经验格里姆的色散修正）-进行了比较。两个突出的结构吸附性能被公开在所有的计算集：一个不对称的鞍形变形的CoTPP与一个增强的倾斜向上弯曲的吡咯和一个单一的吸附位点，其中的Co中心占据一个桥的位置和一个分子轴（沿着的方向降低对相反的吡咯）是与密集的< 1（1）在bar 0>衬底方向对齐。Cu（111）和Ag（111）表面之间的相似性延伸到具有相似的电子再分布和分子充电的界面电子结构。然而，这两种基板之间的微妙差异揭示与偏置依赖STM模拟，特别是在低偏置成像范围。STM计算强调了常用的GGA + D2 DFT框架定量预测前线分子轨道（MO）的能量位置的困难。(C)© 2014 Elsevier B. V.保留所有权利。
The cobalt tetraphenyl porphyrin (CoTPP) molecule and its adsorption on clean Cu and Ag surfaces are comparatively analyzed within the Density Functional Theory (DFT) framework. Different sets of exchange-correlation functionals - the Local Density Approximation (LDA) and the Gradient Generalized Approximation (along with the PEE functional and the semi-empirical Grimme's corrections of dispersion) - are compared. Two prominent structural adsorption properties are disclosed in all sets of calculations: an asymmetric saddle deformation of CoTPP with an enhanced tilting of the upwards bent pyrroles and a single adsorption site where the Co center occupies a bridge position and one molecular axis (along the direction of the lowered pair of opposite pyrroles) is aligned with the dense-packed < 1 (1) over bar0 > substrate direction. The similarities between Cu(111) and Ag(111) surfaces extend to the interfacial electronic structure with similar electronic redistribution and molecular charging. However subtle differences between the two substrates are revealed with bias-dependent STM simulations, especially in the low-bias imaging range. The STM calculations underline the difficulty for the commonly used GGA + D2 DFT framework to quantitatively predict the energy positions of the frontier molecular orbitals (MOs). (C) 2014 Elsevier B.V. All rights reserved.